JPS6154010A - Electromagnetically controlled magnetic conveter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetically controlled scanning magnetic transducer and more particularly relates to an electromagnetically controlled scanning magnetic transducer in which the location or position of the recording/playback area within the transducer is determined by electromagnetic rather than mechanical means. Obtaining high relative transducer/recording medium velocities is of great importance in broadband magnetic signal distribution for controlled magnetic transducers. Increasing the speed of is limited by mechanical limitations associated with high speed feeds as well as the resulting large consumption of the media.

Rotating head transducers utilized in magnetic tape recorders represent a significant advance in increasing relative head/tape speeds. In this case, the transducer rotates at a high speed in contact with a relatively slowly advancing magnetic tape; rotary-scan recorders have two types, commonly referred to as transverse-scan recorders and helical-scan recorders, depending on the angle at which the transducer sweeps the tape. There are two basic types. There are many problems with obtaining the desired accuracy and repeatability of the signals recorded by a rotating drum recorder, for example with regard to the rotating drum, the transducer structure and the location of the transducer within the drum. Mechanical tolerances must be maintained. at the same time,
For the longitudinal tape speed, the drum rotational speed [1-- must be maintained accurately.

Electromagnetically controlled I sign 7I! In a magnetic recorder that utilizes a full rectangular transducer, the drawbacks associated with mechanical rotation of the transducer are eliminated. In this case, the transducer is fixed and spans the width of the transducer, so that high scanning speeds are obtained by electromagnetically scanning the signal to be transduced across the recording medium.

Certain known scanning magnetic transducers have magnetic stacks (plates) separated from each other by non-magnetic spacers.

Each laminate constitutes a closed magnetic circuit constituted by a transducing gap. The laminate has legs with controlled widths that increase in opposite directions on opposite sides of the transducer, and the legs are connected to a control winding. The scanning operation is performed by gradually saturating the legs on opposite sides of the transducer, fL, so that only one laminate remains in transducing mode at a time. The location of the activated laminate is controlled by the control current fL applied to the control winding.

In a conventional converter using this type, by sequentially blocking the magnetic circuit of each laminate,
That is, by cutting off the conversion magnetic flux path, scanning is performed and reduced. Since a leg of variable width must be used, the controlled width portion, and the resulting blocking area, must be located at a distance from the transducer spacing and the transducer plane. As a result, the unsaturated portion facing the recording medium is more likely to pick up interference from adjacent active laminates or stray magnetic flux from adjacent recording signal tracks on the medium. Then, these picked up signals are re-recorded on the medium 9, and during reproduction, they may leak into the magnetic circuit of an adjacent active element, causing complete deterioration of the reproduced signal. The above drawbacks become more significant as the recording frequency and recording density increase.

A further notable drawback of such prior art transducers is that each magnetic laminate in the stack is physically and magnetically adjacent to the
It must be isolated from the I-layer board. Therefore, only incremental or scanning movements across the medium are possible, which can be achieved by sequentially switching on and off the magnetic circuits of adjacent A-layer plates, i.e. not continuously, but in discrete steps. Do it in a certain manner. Further, the track width must be the width of at least one laminate, and can only be adjusted to integral multiples of this width. The above is useful for high frequency broadband recording/playback on narrow tracks where continuous scanning over the narrow tracks and accurate positioning of the transducer elements on the narrow tracks is a prerequisite for high quality performance. This is particularly inconvenient.

The above-mentioned disadvantages are overcome by the scanning transducer according to the invention by means of magnetic control means which selectively saturate the core portion adjacent to the transducing interval and facing the recording medium. Each saturated core section defines an adjacent unsaturated section, and control means are disposed within each core section to ensure that the desired steep permeability versus flux density gradient is obtained across the transducer width. It is becoming more and more like that. The unsaturated core portions on opposite sides of the transducer overlap to define a conversion region of desired width extending across the conversion interval.

In a transducer according to the invention, interference by non-working parts of the transducer core, or pick-up of stray magnetic flux, is substantially eliminated.

Also, preferred embodiments of the invention do not require the use of separate discretely actuated magnetic laminates. Thus, the location of the high permeability conversion region can be controlled continuously along the entire width of the transducer by said electromagnetic control means. Any desired conversion region width can be obtained by selecting the corresponding control current magnitude. Thus, the conversion region width is not limited to the width of one or more conversion laminates, as in prior art transducers. Consequently, in a non-laminated embodiment according to the invention, said conversion region can be narrowed or widened in a continuous manner by electromagnetic means according to the invention, and vice versa.

According to one preferred embodiment of the invention, the desired steep magnetic flux density versus permeability gradient across the transducer width is angled relative to the transducer plane and the transducer spacing plane. @
is obtained by providing each opposing core with a control winding to be removed. The mechanism forms a wedge-shaped saturable core portion including the area between the transducer surface and the transducer spacing surface. The wedge-shaped portions of the opposing cores are oppositely oriented so that their cross-sectional areas increase in opposite directions on one side of the conversion interval. The cross-sectional area including each core surface is
By applying a corresponding control current to the control winding,
Selectively saturated.

The cross-sectional area of the saturated core number 9 defines an unsaturated high permeability transduction region that extends across the transducer plane over the transduction interval.

In another preferred embodiment of the invention, the desired steepness is achieved in said transducer face by providing a controlled flux path with a constant cross-sectional area about tl and a length that increases in opposite directions across the width of each core. Give everything.

Yet another embodiment of the invention includes a laminated core structure consisting of a plurality of magnetic laminates separated from each other by conductive laminates. Guide 1! A drive line extends through each core at a selected distance from the transducer plane and the transducer spacing plane, each portion of the drive line connecting with a conductive laminate. If the control current is differentially switched, the control current flows through the drive line, and the transducer surface touching the conversion interval is selected A7.
'c Saturate the magnetic laminate section. In this example, a laminated core structure is provided and eliminates all interference (crosstalk) pickup at the transducer plane.

In order to make the explanation of the operating principle of the electromagnetically controlled scanning transducer according to the invention easier to understand, the operation of electromagnetically controlled scanning will not be considered at first, and the basic transducing operation of the known magnetic transducer will be described in FIGS. 1A and 1A. 1B, the scanning operation described above will be described with reference to FIGS. 1C and 1D.
This will be explained with reference to the figures.

FIG. 1A illustrates a magnetic transducer 20 having a conventional configuration, which includes opposing magnetic core portions (hereinafter referred to as cores 21, 22) having a transducing spacing of 26 t and a defined magnetic field of 27.28 t. A converter winding window 24 is provided to accommodate a converter winding 25. The converter gap 26 is formed of a non-magnetic material, such as silicon dioxide or glass, as is well known in the art. 1. When a recording signal current is applied to the transducer winding 25 from, for example, a signal source 7 and recorded on a magnetic medium, such as tape 42, a magnetic field is generated within the transducer, as represented by magnetic flux lines 16. The magnetic field emanates from the transducer spacing 26 in the form of a fringe magnetic flux and engages the tape 42, which is shown in the first figure as transparent, and which
A portion 41 of the facing transducer 20 (hereinafter referred to as surface 41) is visible. The peripheral magnetic flux provides a magnetic pattern on tape 42 that corresponds to the signal of winding 25.

For example, the magnetic tape passes through the conversion interval 26 in the direction of the arrow 43,
By advancing the tape, a changing magnetic signal pattern is recorded along the magnetic tape as shown by the arrows in FIG. 1B.

When the transducer 20 is utilized as a playback head for reproducing the entire previously recorded NFC signal, as shown in FIG. , the magnetic flux 16 across the transducer winding 25 picked up by the transducer 20 is converted by the transducer 20 into an electrical signal proportional to the recording flux.

As illustrated in FIGS. 1C and 1D, according to the present invention, the transducer surface 41 has a hatched saturation region 57.
As shown at 58, opposite sides of the conversion interval 26 can be selectively saturated. The saturation of said regions 57,58 is carried out by control means 8.9 (shown in dots) associated with each core 21,22 of the transducer and its respective IL. Said control means 8.911m are constituted by respective control windings (not shown) each connected to one of the cores 21.22 in a manner as will be explained in more detail below. , control current 1., I, t-, each -
1721,: The magnitude of the control current I, which induces a control magnetic flux 47.48t in 22, is such that the magnetic flux induced by that n is as described above, and is shown in the hatched portions of Figs. 1C and 1D. A region 57.58t- with nt width W, , W, selected in each core half as shown in FIG.
Selected to saturate. Said saturation region 57.
58 defines each adjacent high permeability unsaturated portion, ie, region 40.461, that overlaps over the conversion interval 26. The molded portion 40.46 defines a high permeability conversion region 56 of width W extending across the space 26. It will be clear from FIG. 1C that the total conversion interval width w = W, +W, +Ws = constant.

One control current, for example 1. By increasing the total magnitude of the control current l and proportionally decreasing the magnitude of the other control current l, the widths W, SW, of the respective filters change proportionally, and the transformation region 56 becomes It can be selectively moved along the width W of the space 26. For example, if one wants to scan the transducer region 56 t-periodically at high speed along the transducer width W,
Varying the magnitude of both currents I,,I,oppositely and linearly, it causes a saturated portion 57, 580 width W,
, W, 2 A control circuit is utilized that varies proportionally. K to maintain a constant width W of the conversion area 56 during scanning, 6
It is necessary to keep the sum of the varying control currents constant, i.e., I, -) - I, = constant. By changing W, +W, t-, sw,' of the transformation area 56 can be continuously changed. As a result, the transformation area @W can be continuously narrowed or widened, or vice versa.

As can be seen from FIG. 1C, a transducer flux path 16 extends 9 around the winding window 24 and intersects the transducer [25].

As the control magnetic flux line 47.48 spreads 1,000 lines with respect to the converted magnetic flux 16, the magnitude of each control current becomes equal to the control magnetic flux 47.48.
1E is selected not to couple with transducer #j 25 to prevent any interference with signal flux 16. FIG.
0 is shown as an example of an operating mode used for recording and/or reproduction. In order to show the magnetization pattern corresponding to the converted magnetic flux 16 in the converter 20, the conversion interval portion 26 is sufficiently enlarged. This is shown in the diagram. In Figure 1E,
The magnetic medium, e.g. tape 24, is oriented vertically, ie, in the direction of arrow 4.
It is delivered in three directions, in close contact with the transducer spacing 26 and approximately perpendicular to the transducer width W. In this mode of operation,
The electromagnetic control means 8.9 periodically control the area 57.58t.
and by differentially saturating the region 57. Each control means 8.9 adjusts a selected width W,, W, of each opposing magnetic core 21.22 of the conversion interval rb (
It can be seen that 'n is saturated. The difference between the composite @W, +W, and the core width W determines the resulting width W, (W, = W - (W, +w,)) of the transformation area 56. As already mentioned, the composite width By changing W, +W, the conversion area width W can be changed.

35 (FIG. 1E), the position of the transformation area 56 moves along @W, i.e. in the direction indicated by the arrow 10, and the widths W, , W, with respect to each other. On the contrary, it changes linearly and holds the width W, y2 of the transformation area 56 constant. In the above scanning operation, commonly referred to as lateral distribution/reproduction, the width W corresponds to the scan length on the magnetic tape 42. This type of record is
It is characterized by a magnetization pattern that spreads approximately perpendicularly to the scanning direction indicated by arrow 1o, and the magnetization pattern is
It is then recorded along parallel tracks 35 extending approximately perpendicularly across the width of the chip 420. The length L of the conversion interval 26 corresponds to the recorded track width TW. In the recording mode, the magnetic state of the tape is determined by the direction of the recording magnetic flux at approximately the "trailing edge" of the scanning area 56 as it advances along the track 35 by the scanning operation. It can be seen that the track area width W is comparable to the length of the spacing of a normal rotating magnetic transducer used for lateral recording.Therefore, in order to obtain the necessary high resolution, the track area width W. must be narrower than the shortest wavelength to be recorded.
An example of another mode of operation of the scanning magnetic transducer 20 of FIG. However, unlike in FIG. 1E, the transducer 2
When 0 is used for recording, the saturation area 57580 width W,
, W, are kept constant by the control means 8.9.
Fixed position and constant @Ws of conversion area 56 due to L, VC
is maintained. The foregoing is based on the control current 1. provided by means 8.9. This is done by maintaining ,I, to a selected constant magnitude. The resultant magnetization pattern obtained on recorded track 13 is that the transducer 20 of FIG.
When used to reproduce a signal such as that recorded on 3, the widths W, , W, are differentially changed by means of a control means in the direction of n indicated by arrow 10.11. Also,
That is, the conversion area 56 can be repositioned over the width W of the track 13. Said mode of operation maintains an optimal position of the conversion area 56 on the recorded track;
This can be particularly useful for optimizing recording/playback performance.

The latter mode of operation can be utilized when reproducing signals recorded on, for example, lateral, helical, or longitudinal tracks of a magnetic medium.

As mentioned above, by simply changing the saturation region width W, SW, of each core, the desired recording track width Wl can be changed to a different, narrower reproducing track width W,', for example. You can also choose.

Other operators may require 71. for a particular recording method. From the above description, it can be seen that in all of the above modes of operation, the transducer of the present invention is It can be seen that in that respect, and close to the conversion interval, it is saturated.As a result, it is also susceptible to any interference from the inactive tm-blocked core part, or even to the bibukurup of stray flux. is removed.

In order to obtain high quality performance with a scan converter according to the present invention, it is desirable that the boundaries between adjacent saturated and unsaturated portions of the core 21,22 be well defined. The foregoing means that opposing magnetic cores and control windings are arranged within each core in such a manner that the maximum rate of change in permeability between adjacent cross-sectional dimensions of each transducer core is obtained over the transducer width W. This is done by placing it in n. The foregoing indicates that the selected portion of each core surface is saturated by the control current so that no significant magnetic flux passes through it, and the immediately adjacent adjacent region is required for the conversion of the information signal. Ensures that it remains sufficiently magnetically permeable. As a result, converter 2
The performance of 0 is determined by the steepness of the magnetic permeability versus magnetic flux @ degree gradient between each adjacent saturated and unsaturated region in each core. ) is the well-known characteristic of magnetic permeability m versus magnetic flux density B. As you can see from its characteristics, 40
Although a relatively high magnetic permeability m greater than 0 can be obtained with a magnetic flux density rIILB less than B1-4000 Gauss, said high magnetic permeability is sufficient to perform the desired conversion operation. The saturation magnetic flux density of the material is approximately B=6000 Gauss, corresponding to a magnetic permeability of less than 100, as shown in FIG. As a result, in order to obtain the desired fast transition between the high permeability region and the adjacent saturation region in the transducer core, the permeability must be lower than 100 to 4.0 in the direction of
It must change rapidly to more than 00.

A preferred embodiment of an electromagnetically controlled scanning magnetic transducer according to the present invention will now be described in detail with reference to FIG. 2A.

The magnetic transducer 20 has two corresponding cores 21.22k with opposing magnetic poles 27.28' that are smoothly overlapping and tangential to the polished transducer spacing surface 23.0 winding window 24 on one side. It is provided in the core 21.22 of or n-tJn, and accommodates the conversion winding 25. A suitable non-magnetic material is provided between the pole faces 27 and 28, and the conversion spacing 26 is obtained using conventional conversion spacing forming techniques.
Ru.

A transducer surface 41, shown in FIGS. 2B-2D, facing a magnetic medium, such as tape 42, extends in a plane generally perpendicular to spacing plane 23. The transducer may, if desired, be chamfered as shown at dotted line 18 to obtain the desired shape and transducer spacing depth by well-known chamfering techniques. An important feature of the embodiment of FIG. 2A is that apertures 3L32 are provided in each corresponding core 21.22, so that these apertures are connected to the transducer spacing plane 2.
3 and the transducer face 41, extending across the entire width W of the transducer 20 at an angle of 7 IL to 1 IL with respect to both the transducer surface 41.

The control winding 38.39 has its portion 51.52 opened at the opening 31.
．． 32, IL is wound around each core 21.22 times 9 in such a manner as to extend through 6 paths. In the preferred embodiment of FIG. 2A, the cores 21,22 are constructed as two identical core halves, for example from a ferromagnetic block of PS52B, or a single crystal 7E2. Apertures 31,32 run through the width of each core half,
That is, from the upper side 33.34 to the opposite lower side 36.3
7 navel can be obtained by rubbing the diamond. Each core half 21.22 has a spacing surface 2
3, they are overlapped smoothly and polished. A suitable non-magnetic transducer spacing forming a glass-like material is provided on one or both core surfaces 23 by vacuum sputtering. Thus provided n core halves 21.22 t-! One core half is assembled by rotating it by 180 degrees relative to the other core half rL, so that its upper and lower faces are reversed fL, faces 23 and 41.
Opposing cores are obtained in which the apertures 31, 32 are arranged antisymmetrically with respect to each other. Thus, in the assembled opposing transducer cores 21.22, the control winding apertures 31.33 extend at an angle 17' (opposed to both the transducer spacing plane 23 and the transducer plane 41). Part f'
The LFC core utilizes well-known bonding techniques to transform the spacing surface 2
3 and are glass-bonded to each other to obtain a conversion interval 26.

Moreover, the opposing cores 21 and 22 may be made of a common solid block of magnetic material, if desired. In that case, the groove with the desired @ corresponding to the length of the conversion interval is
For example, it is provided inside the surface 41 by grinding. Subsequently, the groove is filled with a suitable non-magnetic material, and the conversion interval 2 is
6 is obtained. The control winding 38.39 then differentially saturates the selected portion, with the winding window 24 obtained by V-cutting across the width of the transducer using well-known cutting techniques. ,
As already mentioned in Figures 1C and 1D,
Unsaturated high permeability conversion region 56 extending over conversion interval 26
I get it.

As mentioned above, in order to obtain a selected saturation region in the face 41 of each core 21.22, each control current I, , I, is controlled by a control winding as described below, for example using the control circuit shown in FIG. 3A. It is fed to lines 38,39.

In a preferred embodiment, the control currents I,,l, are varied differentially and periodically scan over a transducer field having a constant width over the width W of the transducer.

Information signals are recorded or reproduced by the IL along the horizontal tracks 35 of the magnetic tape 42 moving in the vertical direction, as shown in FIG. 2B. For example, the current value I,
If ,I, is held constant, the transformation domain occupies a constant position. The above application may be useful for recording along longitudinal tracks such as shown at 13 in FIG. 2D. Vertical, TFC recorded on a spiral track/
During playback, the position of the transform region can be stepped from track to track. In another application, the recorded helical track illustrated in FIG. It can be moved across the width of the track to obtain optimal playback performance.

FIG. 3A illustrates an example of a control circuit 54 that drives the transducer 200 control windings 38, 39 of FIG. Side 4
It is used to control the position t' of the converted track area in 1. In this embodiment, the transformation area 56 is the first
As shown in FIGS. E and 2B, the magnetic tape 42 is periodically scanned along a lateral track 35. However, the control circuit 54 is also suitable for various operating modes of the transducer 20 when utilized in other recording/playback applications such as those previously described.
4 utilizes a control voltage source 61t which generates a periodically changing control voltage Vc2. The voltage Vc is changed by the same circuit into differentially varying control currents I, , I, as follows. The voltage Vc has a feedback resistor 64 via a resistor 62f, and is applied to the inverting input of a first operational amplifier 63 constituting a voltage follower. The output of the amplifier 63 is connected to the inverting input of a second operational amplifier 66 having a feedback resistor 67 via another resistor 65t.

The operational amplifier 66 inverts the output signal of the operational amplifier 63. The output of the first amplifier 63 is also connected to the feedback resistor 70
f: There is also a resistor 68 at the inverting input of the third operational amplifier 69 having f! r: Connected via. Second operational amplifier 6
The output of 6 is connected via a resistor 71 to an inverting input of a fourth operational amplifier 72 having a feedback resistor 73. An adjustable potentiometer 74 is connected between the negative voltage source and ground to provide an offset of the control current.

The output of the potentiometer 74 is connected via a resistor 75 to an inverting input of a third operational amplifier 69 and via a resistor 76 to an inverting input of a fourth operational amplifier 720, respectively. The output of the third operational amplifier 69 is connected to the first control winding 38 of the converter 20;
is connected to the inverting input of amplifier 690 via feedback resistor 70. Similarly, the output of the fourth amplifier 72 is
The other terminal of the control winding 39 is connected to the inverting input of the operational amplifier 72 via the feedback resistor 73. The connection between coil 38 and resistor 70 is grounded through resistor 78 as well as through coil 39.
The connection between the resistor 73 and the resistor 73 is grounded via the resistor 78. Said four operational amplifiers 63, 66, 69 and 7
2. Each non-reflective input is grounded. amplifier 697
2 and resistors 70.77 and 73.78'
n corresponds to the first and second current sources, respectively.

The voltage Vc from the voltage source 61 is applied to the portage follower 63.
, 64i to the first current source 69.70.77 f
L, the first current source 69.70.77 has an input voltage V
A control current 11 directly proportional to c is applied to the first control winding 38.

Further, the voltage obtained from the output of the operational amplifier 63 and then inverted by the operational amplifier 66 and the resistor 67 is applied to the second current source 72, 73, 78.
．． 73.78 is the control current I that is inversely proportional to the input voltage Vc,
The voltage applied to the second control winding 39 is offset 1 of the desired control current by the potentiometer 74 connected to the 0L) voltage.
, is set, but the offset l, of the control current in this example is intermediate between the minimum and maximum control current values, i.e., I, = (Imax-Imin), as described in detail below with respect to Figure 3B. / 2 (!:
From the above description, if the voltage Vc changes periodically between Vcmin and Vcmax as shown in FIG. A control current I that varies approximately linearly with each output of the second current source,
,I,. Therefore, the control current I,
I.

vary differentially, that is, in opposite directions with respect to each other, and approximately linearly in proportion to the input voltage Vc, as shown in FIG. 3B, as defined by the following equation: .

i.e. I,=KVc+I.

■□=-KVc+1° However, K and I· are constants based on the parameters of the circuit shown in FIG. 3A, and can be derived from the circuit. Referring to the complete history of the preferred embodiment in FIG. 2A, currents 1. ．．
1. is a control winding portion 51.5 extending through the magnetic core.
The control current 1. induces magnetic flux in the magnetic core surrounding 21r. , I, are utilized to saturate selected regions of the magnetic core 21.22 in the plane 41 and obtain a dissonant high permeability track region in said electrophase region according to the invention, as explained below. Ru.

In FIG. 4, the transducer 20 according to the invention is shown in more detail. The two pairs of imaginary planes 44.45 and 59.60 are shown superimposed on the longitudinal axis of the aperture 31.32, respectively. Said 44.45 is parallel, and is a line parallel to the conversion interval plane 23, and the upper and lower side surfaces 33.34
and 36.37 are adjacent to each other. Surface 59.60
is in contact with the side surfaces of these ILs by a line perpendicular to the conversion interval plane 23. From FIG. 4, it can be seen that the imaginary plane 44.45.59.60 side 33.34.36.37 spacing plane 23 and plane 41 are two oppositely oriented planes extending on the opposite side of the transformation spacing plane 23. The wedge-shaped part 49.50t-forms in half. The wedge-shaped part of the control current I, ,
The portions of the magnetic core 21,22 that are to be selectively and differentially saturated by I, by which the desired conversion region 56 is defined are shown.

The wedge-shaped portion 50 is shown in an enlarged perspective view in FIG. Since the wedge-shaped portions of both oppositely oriented wedge-shaped portions are generally the same, the following description regarding wedge-shaped portion 50 generally applies to wedge-shaped portion 49 as well. As can be seen from FIG. 4, the edge 30 of the wedge-shaped portion 50 in the fifth stage is
For a given width W of the transformation interval 26, which is defined as the tangent point of It can be imagined as being divided into mutually parallel cross-sectional areas L1 to Ln along which the acoustic surface area increases.

It can be seen that the wedge-shaped portion 49 facing away from the transducer 200 has a corresponding cross-sectional area (not shown) that increases in the opposite direction. With further reference to FIGS. 4 and 5, when a current I, is applied to the control winding i 39, the corresponding magnetic flux shown by the magnetic flux lines 48 spreads through the turns of the winding section 52. is induced in the core 22. Since the magnetic flux lines 48 do not extend across the transducer interval 26 nor intersect the transducer winding 25, interference between the control flux and the transducer signal flux within the transducer is always minimized. .

To ensure proper scanning movement along the transducer width for lateral recording or reproducing, oppositely varying currents I, ,
The value of I is the control magnetic flux 47. induced by that IL.
48 are selected to successively saturate Ln from the continuously increasing cross-sectional areas II of the wedge portions 49.50 which are oriented one against the other within each magnetic core half 21.22. . For example, when an increasing current I,2 as shown in FIG. 3B is applied to the control winding 39, the cross-sectional areas Ll to Ln in FIG. It is gradually saturated from the maximum part to the maximum part. 7'Lfc wedge-shaped portion 49.50 is oppositely directed by periodically incrementing the control current in one control winding and proportionally decreasing the control current in the other control winding periodically. Each portion Ll to Ln of is saturated periodically and differentially. In the preferred embodiment of FIG. 4, the sum of the differentially varying currents I, -1-I is kept constant, and a constant conversion area 56 is applied to the transducer surface 41 like the upper air. Obtain the width W,=,−. From the above description, it can be seen that the magnetic permeability of the saturated region is approximately equal to that of air, but the overlapping unsaturated region has a relatively high magnetic permeability because it is necessary for recording/reproducing signals. From the characteristics in Figure 3B, the control voltage is -Ycmin25h.
It can be seen that by changing +vCmaxVc from +vCmaxVc, the control current value 1 changes by ImaxVc. However, Ima
x is chosen to be the saturation current level Isa.

l5at corresponds to a current value sufficient to saturate the entire cross-sectional area Ll to Ln, ie all wedge-shaped sections without leaving any unsaturated regions. Since it is necessary to leave an unsaturated region in each wedge-shaped portion 49,50 in order to obtain overlapping transformation regions, the maximum control current Imax must be selected to be below the saturation current level l5at. . As already noted, the wedge-shaped portions 49, 50 are imaginary and are shown solely to aid in the overall description of the operation of the preferred embodiment of the transducer according to the present invention. Preferably, the openings 31.32 in the core halves 21.22 are arranged such that they have approximately square cross-sections Ll to Ln. By this, plane 41 fj! : It is ensured that the containing wedge-shaped portion 49,50 is saturated prior to saturating another core portion further y11 from said surface portion. At the same time, in FIG. 7B, each corresponding to the characteristic of FIG. 6 and oppositely oriented wedge-shaped portions 49. minimize the control current required to saturate.
50 one side and two related Ti folds rLfr
- An example of the magnetic flux density vs. permeability characteristic 53.53a is shown. Figure oi7A is a front view of the wedge-shaped section 49.50 of Figure 4 rotated by 90 degrees. Hatched part 5
7.58 indicates the saturated region, i.e. the core part metal having a magnetic permeability of less than 100. The other core portions in Figure i 7 A 1 show unsaturated high permeability regions 40, 46t having a magnetic permeability of 400 or more. The conversion region 56, which extends over the conversion interval 26 and is formed by overlapping unsaturated high magnetic permeability regions 40.46, corresponds to the overlap 2fc portion of the superposition characteristics 53.53a exhibiting a magnetic permeability of 100 to 400. i7a figure and l! From Figure 7B, it can be seen that a well-defined transformation region 56 requires characteristics with as steep a permeability versus flux gradient as possible. The above requirements are met by selecting a transducer core material with a steep characteristic curve and by ensuring that large changes in magnetic flux density occur between adjacent cross-sectional areas over the entire scan length. obtained by designing a wedge-shaped part. In order to increase the magnetic permeability gradient throughout history, it must have magnetic anisotropy and
It is desirable to use a tightly heaved core material whose axis of easy magnetization is oriented perpendicular to the transducer spacing plane. To further maximize the magnetic flux density gradient between two adjacent cross-sectional areas and obtain the desired maximum permeability versus magnetic flux density gradient, the shape of the wedge portion is approximated to the characteristic curve of FIG. 6. That is, the exponentially increasing cross-sectional area Ll to Ln of the wedge-shaped portion 49.50
It is desirable to obtain 2. This means that core 21.22
This is achieved by providing an exponentially shaped aperture 31,32i extending through i. However, it may be difficult to form such an opening in a solid core made of a magnetic material due to design considerations.

The manufacture of the transducers of FIGS. 2A and 4 is simplified by the embodiments of FIGS. 8 to 11 described below, particularly with regard to obtaining an exponentially wedge shape.

FIG. 8 is an exploded perspective view showing a preferred embodiment of a laminated magnetic core body 81 formed of a plurality of thin magnetic laminated plates 72 having a thickness of, for example, 0.001 inch, where 1 inch is approximately 2.54 cIn. However, for clarity, only four laminates are shown. The laminate 72 may be etched by a thin plate of a suitable phosphor, such as Permalloy or Mumetal HiMu80. However, if all of the laminates are stacked as shown in FIG. It is adapted to be gradually displaced into the laminate in such a manner as to accommodate the control winding 39.

The laminate of FIG. 9 is glued using well-known bonding techniques, e.g. with epoxy, to form one half of the core 81 to the laminate of FIG. It corresponds to the core. Two opposing laminated half-cores 80, 81 are overlapped at each spacing surface 23,
A non-magnetic conversion spacing material, such as silicon dioxide, is vacuum sputtered thereon using known sputtering techniques. Opposing core halves 80.81 The one core half is rotated 180 degrees relative to the other core half as indicated by arrow 15 in FIG. 10, as already explained in FIG. Each control winding opening 3132 is connected to the spacing surface 23 and the surface 41.
So rL-f: It is assembled in such a manner that it spreads antisymmetrically with respect to rL. The assembled core halves 80, 81 are epoxied together using known adhesive techniques. The resulting laminated core structure 80.81 is chamfered at the transducer face 41 to obtain the desired shape as shown at 41A in FIG. 11, as well as to obtain the desired depth of transducer spacing. desirable. Thereafter, said control winding 38.39 is connected to the opening 31.3 as described in FIGS. 2A and 4.
Each core half 80.81 is constructed around each core half 80.81 by a respective portion 51.52 of seven rL extending through the core. A converter winding 25 is wound approximately symmetrically around the back side of the core 80, 81 through the winding window. Control winding 38.3
The relative placement of the converter winding 25 with respect to FIG.
Note that the embodiments of FIGS. 8 through 11 are less important than the embodiments of FIG. However, it has the advantage that it is not necessary to drill the core in order to provide a control winding window. It will be appreciated that by properly positioning the control winding windows within each stack 72, any desired shape of the window, such as an exponentially shaped window, can be obtained relatively easily.

Another preferred embodiment of an electromagnetically controlled scan converter according to the present invention is shown in FIGS. 12-16. As will be seen from the following description, this embodiment has advantages over the previously described embodiments in that it provides a more uniform saturation of the cross-sectional area in the direction perpendicular to the conversion spacing plane. Furthermore, desired magnetic core geometries containing exponentially increasing cross-sectional areas can be obtained in a simplified manner. At the same time, a permeability/flux density gradient of the desired shape is obtained between the saturated and unsaturated regions of the transducer surface, thereby increasing the definition of the transducer region.

In FIG. 12, a plurality of magnetic laminates 301 are stacked to form a laminated core stack 305. Each laminate has a central opening 3 which acts as a control winding window.
A sealed control flux path 304 having 14 holes is formed in the four six laminate faces 303 around the control winding window 3140.

Adjacent laminates in stack 305 control flux path 3
04 increasing lengths of total blindness. This is accomplished by gradually increasing the centering of adjacent stacks in the direction of arrow 312, as shown in FIG. 12, thereby increasing the reluctance of the magnetic flux path. Each laminate has the same thickness and a substantially constant [302? It is desirable to have one. - As an example, the laminate 301 is made of Mumetal ■ Old Mud Permalloy having a thickness of 0.0001 to 0.001 inches.
The fc may be made of an amorphous metal. converter #j
A groove 315 for accommodating I is provided inside the conversion spacing surface 308. The depth of the laminate 301 may be incremented linearly, exponentially, or any other desired relationship of IL to obtain the desired increment of magnetic flux path length. In this embodiment, a desired steep magnetic permeability/magnetic flux density gradient metal is created between adjacent cross-sectional areas 303 across the transducer width W for the reasons already explained in the above-mentioned embodiments of the transducer according to the present invention. An exponential increment is given to obtain I. The laminates 301 are glued together in the same manner as in the embodiments described above in FIGS. 8-11. Resulting half-core stack 305
is illustrated in FIG. two corresponding stacks 3
05.305a utilizes the same technique as previously described in the above embodiments of FIGS. When assembled, they are connected to each other as shown in FIG. 14. It can be seen from FIG. 14 that the opposing core products WI on each side of the conversion interval are oriented in opposite directions as follows.

These core stacks are assembled such that the control flux path length 304 of each core 305, 305a increases in opposite directions across the transducer width W.

The increasing flux path lengths of these ILs serve to obtain differential saturation on opposite faces 306 of transducer spacing 307, as shown, for example, in hatched areas 353 and 354 in FIG. 6 width W of saturation region 353.354,
, W, is a high permeability conversion region 333 having a desired width W-
are selected to be reduced in plane 306 by overlapping unsaturated regions, as described above with respect to FIG. 14.As shown in FIG.
Each core half 30 passes through a control winding window 314.314a.
5.305a, preferably the conversion surface 306.30
It wraps around 6a. The conversion signal winding 334 is assembled around the conversion winding window 31 and the core 305.305a.
5. Turn it all the way through.

Translation region 333 can be scanned across the width W of the transducer using, for example, the same control circuitry as previously described with respect to FIG. 3A.

Examples of changes in the design of the converter structure shown in FIGS. 12 to 14 will be described below with reference to all of FIGS. 15 to 16. FIG. 13th in that it has 321
Composite helad core 318 different from the above-mentioned core 305 in the figure
3, the front core 320, the front core 320, and the laminated back core 321 have opposing surfaces 325.3, for example.
Joined together by eboshiki gluing at 27 n2
) spaces are removed. The front core 320 is, for example, P
It may also be made of a ferromagnetic block such as 852B. A groove 322 is provided inside the transducer spacing surface 323 of the front core 320 to provide a transducer winding window. The laminated back core 321 includes a plurality of individual U-shaped laminates 326 in the same manner as previously described in FIGS. formed from. As already explained in FIG. 12, each laminate has a substantially constant width in the direction perpendicular to the control flux path 335 extending in the plane of the laminate as shown in FIG.
329 t-has. ! As in the embodiment of Fig. @14, adjacent laminates have progressively increasing depths in the direction 327 and control flux path lengths that increase in opposite directions, thus increasing in opposite directions across the transducer width W. Magnetic resistance is obtained within each core 318,319. The increment may be linear, but
It is preferably exponential, maximizing the permeability/flux density gradient as already discussed in previous embodiments. The cona 320 and stack 321 joined together form a sealed low reluctance controlled flux path as shown at 335 in FIG. 16. Each back core of stack 321! The RM plates are in close physical proximity to each other to reduce magnetic losses. The opposing core 318 is further oriented in the opposite direction.
．． The assembly of 318a, the conversion to each of the cores, and the installation of control windings are the same as those shown in FIGS. 12 to 14 above, so the explanation thereof will be omitted here. From the above explanation, in the embodiments shown in FIGS. 12 to 16, t1 of the lamination
! rx constant cross-sectional area is maintained in the direction perpendicular to the control flux path, and the length of the control flux path will increase differentially, ie, in the opposite direction of opposing cores 318, 318a. To ensure that transducer surface 306.306a is saturated before saturating other magnetic core sections, in the embodiment of FIGS. 12-16, surface 306.3
It is desirable that the width 329 of the magnetic flux path 304 along 06a is slightly narrower and narrower than the width 329 along the other portions of the magnetic flux path. Another advantage of the embodiment of FIGS. 15 and 16 is that the monolithic front core 320 may be made of a different material than the back core 321.

For example, the front core material has a sharp magnetic anisotropy with the axis of easy magnetization oriented perpendicular to the transducer spacing plane to further increase the definition of the transducer region. Oppositely oriented relative cores 305.305a with controlled flux path lengths increasing in opposite directions
It can be seen by comparison with the embodiment of FIG. 4 that the gradual saturation of is similar to the saturation of the oppositely directed wedge portions of the embodiment of FIG. As a result, Figures 12 to 16
The operation of the illustrated embodiment and the embodiment of FIG. They are similar in that they form high permeability conversion regions that can be scanned. However, the embodiments of FIGS. 12 to 16 differ in that the entire laminated surface including surfaces 306, 306a i is saturated, instead of only that portion being saturated as in the previous embodiment. The laminated cores of the above embodiments are designed to facilitate manufacturing, particularly to easily obtain a desired core shape having an exponentially increasing cross-sectional area. I understand. the result,
The magnetic laminates of the core are in physical contact with each other and there is no need for any magnetic or electrical isolation between them.

Another embodiment of the present invention will be described with reference to FIGS. 17 to 25. Here, it is shown that through each opposing core, in close proximity to both the transducer plane and the transducer spacing.
A control winding in the form of an extending conductive drive line 368, 368a provides saturation of the surface portion. In this example,
The magnetic circuits are isolated from each other by non-magnetic conductive laminates 363.Discrete magnetic laminates 361 are provided in the scan converter half-core 360K. The lamination 363
is electrically conductively connected to the drive line 368, and the magnetic laminate is connected to the magnetic laminate by each of the two conductive laminates and a portion of the drive line between them. A current winding around 361 is constructed. Each magnetic laminate is saturated by applying a controlled current to the surrounding conductive laminates and to a corresponding portion of the drive line extending through the laminate. , by one or more unsaturated laminates, and as will be explained in detail below, scan along the width of the transducer by switching on/off the conductive laminates constituting the current windings, i.e. In addition to saturating the movable transducer surface, this example provides a steeper step permeability/flux density gradient across the transducer surface than prior art transducers.
Another advantage is that Its properties are virtually unrelated to the magnetic permeability versus magnetic flux density properties of the magnetic laminate, as explained in detail below.

A magnetically permeable laminate 361 is stacked and an N1 conductor is inserted between the laminates 363.An exploded view of one of the transducer core halves 3600 is shown in Figure 17. Preferably, the WI is made of an electrically insulating material, such as 0.0001 inch thick silicon dioxide.
362 is sputtered onto each planar surface of each magnetic laminate 361 to electrically isolate it from the conductive laminate 363. Each conductive laminate 363 has a lead wire 364t-
In one example, the magnetic laminate has a thickness of 0. , 001 inches of mu-metal HiMu9Q or amorphous metal, and the conductive laminate is made of copper o, oos inches thick. Each laminate 361.363 has an overlapping opening 366.3 therein.
67, and each laminated plate 363 is electrically connected by soldering, etc., but from the magnetic lamination,
Contains a conductive drive line 368 that is electrically connected but electrically isolated from the magnetic stack.

FIG. 18 shows a top view of the assembled IL7 (laminated half-core stack 360) of FIG. 17. FIG. , and a block diagram of a multilayer switching circuit 371 connected to the stack.
As shown in FIG. 19, two identical conductive laminated switching circuits 371 and 371a are preferably utilized, so only one circuit 371 is shown in detail in FIG. 19 and will be described below. Let's do it. As can be seen in FIG. 19, one end of conductive drive line 368 is connected to one magnetic pole of a controlled current source 372, while the other magnetic pole of the current source is connected to ground. Each lead wire 364 has a conductor 1! It is connected to one of the plurality of outputs 399 of the layered switching circuit 371 .

- By way of example, the conductive IT layer switching circuit 71 includes an up/down counter 430, a programmable read-only memory (P&OM) 433, a transistor 434, a current setting collector resistor 435, and a base resistor 436. I have a lot of them. It is composed of a plurality of transistor switches. The up/down counter 430 has a clock signal input 437, a direction signal input 438, and a preset input PI to Pn 428.
, a load human power 439, and a plurality of outputs Q1 to Qn
431.

Each output 431 is connected to one input 432 of PRIM 433.
It is connected to 几. FROM433 has multiple output DI
to Dn 440, the plurality of outputs are each connected to a pace resistor 436 of one switch 434 of the array 429. Each collector resistor 435
are connected to one of the conductive laminated layers 363 via lead wires 364, respectively. The emitter of each transistor 434 is grounded.

1 of the magnetic transducer 378 obtained by joining two corresponding core halves 360.360a! Magnetic control scanning is the 20th
It is illustrated in the figure. A transducer spacing 381 of a suitable non-magnetic material, such as silicon dioxide, is provided on the transducer spacing surface 380 of one or both of the segmented cores 360, 360a using known spacing techniques. Each core half 360.360a is assembled together in an antisymmetric manner as described below. The core halves are aligned one core half with respect to the other, as shown by arrow 357.
Inverted by rotating 8071 fL% [flow source 37
Conductive port connected to 2.372a, 368.368a
Each end of is inverted with respect to each other, i.e., positioned on opposite sides across the transducer width W. Conversion signal winding 3
82.382a is wound around the core half through the winding window 383 and is used as a recording/reproducing signal winding. Each conductive laminate 363. of each core half 360.360a.
363a is each laminated switching circuit 371, 371a
t- to a current source 372, 372a to sequentially magnetically saturate selected laminate faces of each core half, as described below.

Next, an example of the operation of the scan converter according to the present invention shown in FIG. 20 will be described with reference to FIGS. 21 to 25.

In FIG. 21, a black signal having a frequency corresponding to the desired stack switching frequency is received at the black input 437.437a of the counter 430.430a. One counter, e.g. 4300 angstroms 438, receives a direction signal B, while the other counter, e.g. 4302 K, receives a direction signal having the opposite polarity to said signal B. One of the counters is preset at 428 to an initial count value different from the last count value of the other counter to obtain an offset count value corresponding to line spacing 2, as shown in FIG. When the -10,000 counter, for example 430, counts up to 0 in FIG. 21 as shown in FIG. 21, the -10,000 counter 430a simultaneously counts down as shown in FIG. 21E. 433.433a of P fLOM is the counter 430.430 as shown in Table 1 below.
is programmed to convert the sequential binary count values obtained at output 431 of a to a sequential output signal at output 440.

Table 1゜Binary output of 431 Output signal P of 440]
From Pn Dl 1)2 1)3 D4 D
5 Dnooooooo.

5 11111...O rl 1 1 1 1 1"・1
As is clear from FIG. 19, the output D1 at 440
When any of the Dn is activated, the IL connected to it
A particular transistor switch 434 to 436 is turned on and a particular conductor 1! The laminated plate 363 is connected to a current source via a portion of a lead wire 364, and is also connected to ground. It can be seen that when the top conductive laminate 363 on top of the star 360 is connected to a current source 372, a control current winding is wound around the first magnetic laminate 361. When the next transistor switch is actuated in direction 351, it causes a current winding to be applied to both the first and second magnetic laminates 361, and all magnetic laminates of the stack have said current windings. When the winding is completed, the bottom laminate of the stack is switched off to the circuit. Each magnetic laminate around which a winding carrying a control current is wound induces a magnetic flux around drive line 3680, as illustrated by magnetic flux 376 in FIG. The magnitude of the drive line 3680 control current is selected to be sufficient to saturate a portion of each peripheral laminate with gold. The saturated portion is shown in FIGS. 18 and 2.
In FIG. 0, the ?ching section 377K extends over the range defined by the transducer plane 365, the transducer spacing plane 380, and the drive line 368, as shown.

In comparison to the embodiments of FIGS. 2A and 4, the relatively close location of the drive line 368 to both the transducer plane 365 and the transducer spacing plane 380 of FIG. Volume 15 in Core 21! It can be seen that the location is similar to that of portion 51. However, in the embodiment described, a gradual saturation of the transducer planes in each core is imparted to the control windings by the selected angling of the control winding portions 51 with respect to the transducer planes as well as to the spacing planes. Whereas IL can be obtained by selectively varying the magnitude of the control current t, in this example, the current winding is controlled by a conductive drive line, or the magnetic laminated plate of T. et al. The difference is that only the transducer plane is saturated, thereby reducing the saturation region of the transducer. The saturation region is moved or scanned across the transducer width by switching to different parts of the control current t-drive line. Drive line 3610 plane 3o6
To saturate the t-[IILfc portion of the laminate before saturating it, the drive line 368 is connected to the transducer surface 3.
06 and spacing surface 380 and approximately equidistant therefrom. In FIG. 20, in order to obtain scanning of the conversion region 386 across the transducer width W, one switching circuit, for example 371, is switched in the direction indicated by the arrow 351, while the other switching circuit 3718 e-1 sorL
IL is switched in the opposite direction 352 in synchronization with IL. Thereby, a controlled current from current source 372 connects conductive laminate 36 of one core half 360 as described in FIG.
3 is given sequentially and the other switch is 0.

The switching circuit 371a receives current 1. from the current source 372a.
Conductive laminate plate 363a of t-more-man core half 360a
given sequentially. As in, the control current I is switched,
, 1. The number of active conductive laminates in each core varies in opposite directions and linearly, while gradually saturating the face portions of the cores in opposite directions across the width of the transformer,
The width of the 7'C conversion area is kept constant. Said counter offset Z, obtained by presetting one of the counters with respect to the other counter, ensures that one or more laminates of each stack will be unsaturated at any time with a desired constant width W, 2 Thus, it is guaranteed that a transform region 386 that is equal to M over the transform interval 381 is obtained.

The operation of the scan converter shown in FIGS. 17 to 20 will be described with reference to FIGS. 22 to 25. FIG. 22 shows the surface portion 3 of one side 360 of the portioned core of FIG.
It is a front view of 65 rotated by 90 degrees. Saturated part 37
7 is indicated by hatching. For ease of comparison with the characteristics of FIGS. 6 to 7B, the laminate 36
1 is made of the same magnetic material, preferably mu metal (iMu
FIG. 23, with 3Q selected, shows the magnetic flux density (B) versus permeability (m) characteristic 387 of the transducer face portion 365 of FIG. 22. It can be seen from FIG. 23 that this embodiment has the advantage of obtaining a steep step-like magnetic permeability/magnetic flux density gradient across the transducer @W. The above characteristics are
Each laminate is "wound" separately with a full control current winding.

As a result, a control current is supplied to a particular current winding that surrounds the entire magnetic laminate nl, saturating its surface area completely, and turning off the entire control current IL7 (the adjacent magnetic laminate is free from any control flux). Thus, the desired abrupt change in magnetic flux density versus permeability occurs between adjacent unsaturated and saturated regions of the surface portion, but the change is caused by the change in permeability/flux of the magnetic laminate. It is practically unrelated to density gradients.FIG. 24 shows surface portion 3 of core half 360.360H assembled in the opposite direction as shown in FIG.
65. Rotate by 90 degrees of 365a to get a front view.

The opposite orientation ensures that each control current in each core half is switched in opposite directions across the transducer width and differentially switches the transducer faces on opposite sides of the transducer spacing 381 as explained in FIG. It can be seen that it is saturated. Figure 25 shows the characteristics 387.38 in the opposite direction, where the two characteristics in Figure 23 are superimposed.
7a iAlthough shown in the figure, the detailed IL of the characteristic is the second one.
4 shows the characteristics of one of the core halves 360 and 360a in FIG. High permeability conversion region 386 with good results
is obtained by the area between the superimposed features as shown.

As is clear from the above, the scanning, or movement, of the conversion area 386 along the transducer width W in this embodiment is carried out in nine discrete steps across the transducer width, and each step is
It can be seen that the thickness of the magnetic laminate N, the thickness of the laminate and the insulating layer correspond to the combined thickness. Furthermore, it will be appreciated that other embodiments of the switching circuit 371, 371a are also possible. For example, circuit 429.43 in FIG.
0 and 433, a plurality of resistors (not shown) each having a terminal connected to one conductive laminate
It is also possible to switch the lamination using t-. The value of the resistor connected to the adjacent laminate of each core half is incremented in opposite directions across the transducer width. The other terminal of the resistor of each core is connected to one magnetic pole of the variable voltage source. and the other opposite magnetic pole of the variable voltage source is connected to one end of a conductive drive line. By changing the voltage in each core half in the opposite direction, subsequent laminates in the opposite stack are sequentially differentially saturated as described in the 17th to 25th embodiments. In yet another embodiment, as shown in FIGS. 21B and E,
Instead of scanning the transform domain symmetrically in both directions (with each time interval, 1.,l, being equal), it is also possible to shorten one interval with respect to the other. Therefore,
A relatively long scan interval in one direction and a rapid return of the scanning difference area in the other direction can be obtained by adjusting the timing of the switching circuit 371371a accordingly.

4. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a perspective view illustrating the operation of a magnetic transducer without electromagnetically controlled scanning operation according to the prior art.

The itB diagram is a diagram showing the direction of magnetic particles on the tape recorded by the transducer of FIG. 1A.

FIG. 1C is a perspective view showing the principle of operation of the electromagnetically controlled scanning magnetic transducer according to the present invention.

1ll) is a front elevational view of the transducer according to the invention of FIG. 1C.

FIGS. 1E and 1I are diagrams illustrating various modes of operation of the converter according to the invention of FIG. 1C.

FIG. 2A shows a simplified perspective view fL7 of an electromagnetically controlled scanning magnetic transducer according to a preferred embodiment of the present invention.

Figures 2B, 2C and 2D illustrate the various recording types that can be obtained when utilizing a transducer according to the invention.11.
FIG.

! Figure @3A is a control circuit diagram used to drive the converter according to the present invention.

FIG. 3B is a diagram showing the control voltage vs. control current characteristics obtained by the circuit of FIG. 3A.

FIG. 4 shows in detail the transducer according to the invention shown in FIG. 2A.

5 is an enlarged perspective view of the saturable wedge-shaped portion of the transducer according to the invention of FIG. 4; FIG.

FIG. 6 is a diagram showing an example of magnetic flux density versus magnetic permeability characteristics of a known magnetic material.

Figure i7A is a positive elevational view of the fLfc saturable wedge-shaped portion towards the opposite side of the transducer according to the invention of Figure 4 rotated by 190 degrees;

FIG. 7B shows the magnetic flux density vs. permeability characteristic of FIG. 6, which corresponds exactly IL to one saturable wedge-shaped portion of FIG. 7A.

fA8, FIG. 9, FIG. 10 and FIG. 11 are diagrams illustrating a preferred method of manufacturing the transducer of FIGS. 2A and 4 according to the present invention.

Figures 12, 13, 14, 15 and 16
The figure shows another preferred embodiment of the invention.

17, 18, 19 and 20 are diagrams showing other embodiments of the present invention.

Figures 21, 22, 23, 24 and 25
The figures show the operating sounds of the embodiments shown in Figs. 17 to 20.
It is a figure showing 7L.

In the figure, 8 and 9 are control means, 20 is a magnetic transducer, 21 and 22 are partial magnetic cores 23 are transducer spacing surfaces, and 2
4 is a conversion winding window, 25 is a conversion winding, 26 is a conversion interval, 2
7 and 28 are magnetic surfaces, 31 and 32 are openings, 38 and 39 are control windings, 40 and 46 are overlapping unsaturated high permeability regions, 49 and 5° are wedge-shaped portions, and 51 and 52° are winding portions. 54 is a control circuit, 56 is a conversion region, 57 and 58 are saturation parts, and 72 is a magnetic laminate. I3 10 7I3 RE Near I [3IF 7l6 3B -: E-I6-t] -F-I [E - Day 7I [i 10ζ S
″- (JOul

Claims (1)

[Scope of Claims] (1) In an electromagnetically controlled magnetic transducer, a magnetic core having a corresponding core portion and having a magnetic pole in contact with a transducing gap surface so as to define a transducing gap; control means for selectively saturating surface portions respectively associated with the core portions and proximate the transducing gap, each said saturated portion defining an adjacent unsaturated high permeability surface portion;
A magnetic transducer (2) characterized in that the high magnetic permeability surface portions overlap across the conversion gap to define a high magnetic permeability conversion region. A magnetic transducer (3) characterized in that it comprises a transducer winding engaging a magnetic core (3) A magnetic transducer according to claim 1, in which the transducer gap extends in the direction of the width of the magnetic transducer. and each said control means comprises a control winding extending across the width of one of said core portions and connected to receive a control current to selectively saturate said surface portion. (4) The magnetic transducer according to claim 3, further comprising current applying means for applying the control current to the control winding. (5) In the magnetic transducer according to claim 4, the current applying means applies the control current of a constant magnitude to maintain the conversion region at a predetermined position and a constant width. (6) The magnetic transducer according to claim 4, wherein the current applying means changes the magnitude of the control current,
The magnetic transducer (7) according to claim 6, characterized in that the magnetic transducer (7) is coupled to thereby vary the width of each of the saturation surface portions, wherein the current applying means The magnitudes of the currents are varied linearly and in opposite directions with respect to each other while the control currents are maintained at a constant sum, and the location of the conversion region is varied to maintain its width constant. In the magnetic transducer (8) according to claim 7, the current applying means periodically changes the magnitude of the control current in the direction of the transducer gap width. The magnetic transducer (9) according to claim 6, characterized in that the magnetic transducer (9) is characterized in that periodic scanning of the conversion region is obtained. The magnetic transducer (10) according to claim 3, characterized in that the magnetic transducer (10) includes means for changing the sum of the transducing region widths in the direction of the transducing gap width. Each of the control windings extends across each core portion in an oppositely oriented angular relationship to each of the transducer gap plane and the transducer plane, and is oriented in opposite directions adjacent to the transducer gap. so as to obtain a selectively and differentially saturated core portion in the form of a wedge-shaped cross-section, each said wedge-shaped cross-section having a cross-section increasing in opposite directions on either side of said transducer gap and along its width. The magnetic transducer (11) characterized in that the area is
A magnetic transducer according to claim 10, characterized in that each of said opposing magnetic cores has an opening for accommodating one of said control windings (12). A magnetic transducer (13) according to claim 11, characterized in that the aperture extends in a substantially linear path across the width of the transducer. A magnetic transducer (14) according to claim 10, characterized in that the aperture extends in a substantially exponentially shaped path across the width of the transducer. A magnetic transducer according to Patent (15), characterized in that the increasing cross-sectional area is substantially rectangular and extends perpendicularly to both the transducer gap plane and the transducer plane, respectively. 12. The magnetic transducer of claim 11, wherein each of said opposing magnetic core portions is constituted by a plurality of stacked magnetic laminates, and each said laminate has an opening for accommodating said control winding. said magnetic transducer ( 16) The magnetic transducer according to claim 15, wherein the magnetic laminates of each core are in physical contact with each other (17) Claim 15 16. A magnetic transducer as claimed in claim 15, characterized in that the aperture is displaced to form a substantially linear path. A magnetic transducer (19) according to claim 3, characterized in that the apertures are displaced so as to form a substantially exponentially shaped path, each of said opposing magnetic cores said magnetic flux path, said portions extending substantially perpendicular to both said transducer gap plane and said transducer plane, each providing a controlled magnetic flux path having a magnetic reluctance that increases in opposite directions along the transducer width; Transducer (20) A magnetic transducer according to claim 19, wherein each core portion has a central control winding window for accommodating the control winding, and the control flux path is having a substantially constant width defined by the central control winding window, and characterized in that the increasing reluctance is obtained by providing the magnetic flux path with increasing lengths in the opposite directions. Magnetic transducer (21) A magnetic transducer according to claim 20, wherein each of said opposing magnetic core portions increases in opposite directions along said transducer width to obtain said incremental magnetic flux path length. A magnetic transducer (22) according to claim 19, characterized in that the magnetic transducer (22) has a progressive depth in the direction of the depth of the transducing gap, in which each of the opposing magnetic core portions has a It is constructed by a plurality of magnetic laminations having a sealed central opening corresponding to said central control winding window, with each core succeeding lamination having a depth increasing in the direction of the depth of the transducer gap. A magnetic transducer (23) according to claim 19, characterized in that the controlled magnetic flux path is provided by each planar surface of the stack (23). The magnetic core portion comprises a monolithic front core portion and a laminated back core portion integrally joined therewith and consisting of a plurality of magnetic laminations each having a generally U-shaped central opening corresponding to said central control winding window. 24. The magnetic transducer (24) characterized in that the magnetic transducer (24) is configured and that the increasing reluctance is obtained by providing a subsequent stack of each core with increasing depth in the opposite direction. 24. The magnetic transducer according to claim 23, wherein the monolithic front core is made of a magnetic material having an axis of easy magnetization in a direction perpendicular to the transducer gap plane. The magnetic transducer (26) as described, characterized in that the control flux path along the transducer face has a relatively narrow width with respect to the rest of the core. 3. The magnetic transducer of claim 3, wherein each of said opposing magnetic core portions has a plurality of stacked magnetic laminates separated from each other by non-magnetic conductive laminates, and each said control winding has a conductively connected to the conductive laminate extending across the width of the magnetic core at a selected distance from each of the transducer gap plane and transducer face portion, respectively; conductive drive lines, and the conductive laminate of each magnetic core portion is further coupled to the conductive drive lines to selectively apply the control current to the transducer face portion. Magnetic transducer (27) according to claim 26, characterized in that the magnetic transducer (27) is saturated, comprising: a controlled current source with one pole coupled to one end of the conductive drive line; and a switching means for selectively connecting each conductive laminate to the other opposite pole of the magnetic transducer (28). The switching means sequentially connects adjacent conductive laminates of one core half in one direction to the current source, and sequentially connects adjacent conductive laminates of one core half in the other direction from the current source. An electromagnetically controlled magnetic transducer (29) characterized in that the above magnetic transducer (29) is coupled in a blocking manner, having two corresponding core parts, the magnetic poles of which are coupled so as to define a transducing gap. a magnetic core abutting at a gap plane, each having a portion extending across the width of one of the magnetic core portions in an angular relationship oriented in opposite directions with respect to both the transducer gap plane and the transducer plane; 1st
and a second control winding, the first and second control winding portions, the transducer surface and the transducer gap surface extending across the transducer width to either of the transducer gaps. Oppositely oriented saturable wedge-shaped portions are defined within each said core portion, each having a cross-sectional area increasing in opposite directions on the side thereof, and each of said first and second control windings has a highly transparent coupled to receive a control current that selectively saturates portions defining adjacent unsaturated high permeability portions of the wedge-shaped portions that overlap across the transduction gap and are oriented in opposite directions to define a magnetic transduction region; The magnetic transducer (30) according to claim 29, characterized in that the magnetic transducer (30) is provided with a current applying means for applying the control current to the control winding. Transducer (31) A magnetic transducer according to claim 29, wherein the opposing magnetic core portions are composed of a monolithic magnetic material, and each core has a respective opening for accommodating one of the control winding portions. A magnetic transducer (32) according to claim 29, characterized in that each of the opposing magnetic core portions has an opening for respectively accommodating the control winding. It consists of multiple magnetic stacks stacked in physical contact with each other,
32. The magnetic transducer (33) according to claim 32, and wherein said openings are gradually displaced in successive laminates of each stack to obtain said angular relationship. 34. A magnetic transducer according to claim 32, characterized in that the aperture is displaced linearly. The magnetic transducer (35) is characterized in that the magnetic core has two corresponding core portions with magnetic poles abutting the transducing gap surface to define a transducing gap in electromagnetically controlled magnetic transduction,
consisting of a plurality of stacked magnetic laminates, each having a planar surface and a central winding window, with each core having successive laminates having depths that increase in opposite directions across the width of the transducer. each defining a magnetic core and adjacent unsaturated high permeability laminates each extending through the central winding window of each of the core portions and overlapping across the conversion gap to define a high permeability conversion region; 36. A magnetic transducer according to claim 35, characterized in that the magnetic transducer (36) comprises a control winding that differentially saturates selected laminations of the core portion. In an electromagnetically controlled magnetic transducer (37), the transducer gap is characterized in that the planar surface of the body is provided with a controlled flux path having a substantially constant width defined by the control winding window. a magnetic core having two corresponding core portions with magnetic poles abutted at the transducer gap face such that the magnetic poles are abutted at the transducer gap face, each with respect to both the transducer gap face and the transducer face adjacent to the transducer gap; each said core portion has a magnetic reluctance extending generally perpendicular to the transducer width and increasing in opposite directions along said transducer width, and wherein a control flux path defining a central control winding window is provided by each said core portion; a control winding disposed in each control winding window of each core portion adapted to receive a current and be coupled to selectively saturate a portion of the transducer surface adjacent the transducer gap; The magnetic transducer (38) is an electromagnetically controlled magnetic transducer characterized in that the magnetic poles are brought into contact with the transducing gap surface so as to define a transducing gap, and each of the magnetic poles is made of a non-magnetic material. a magnetic core having two corresponding core portions consisting of a plurality of stacked magnetic laminates separated from each other by conductive laminates, each of said core portions at a selected distance from each of said transducer gap plane and transducer plane; a conductive drive line extending across the width and conductively connected to the conductive laminate and each coupled to the conductive laminate of each of the core portions to selectively apply a respective control current to the conductive drive line; and a switching means for differentially saturating the magnetic laminate at the transducer plane. a magnetic core having two corresponding core portions, each consisting of a plurality of stacked magnetic laminates, each separated from one another by a non-magnetic conductive laminate, with magnetic poles abutting at said transducing gap planes so as to define . and each of the magnetic cores adjacent the transducer gap, each extending across the width of one of the magnetic cores at a selected distance from the transducer gap plane and the transducer plane and in conductive connection with the conductive laminate. first and second control windings constituted by conductive drive lines that selectively saturate a portion of the magnetic laminate, and sequentially applying respective control currents to the conductive laminate of each opposing core; means for successively saturating selected portions of said magnetic stack, with at least one opposing magnetic stack of each core being unsaturated and extending across said transducer gap in said transducer plane. The magnetic transducer described above is characterized in that it provides a high magnetic permeability conversion region that spreads through the magnetic field.